Monday, September 12, 2016

Okay, I’m going to be honest. The last couple of weeks
rocked GeoNet (see what I did there?)....

It all started on the 31 August, a Wednesday, with the Tier
4 Exercise Tangaroa. Tier 4 means a national exercise and that means
everyone, from local, regional and national authorities, participate. It was a
large tsunami scenario; GeoNet played a pretty big role in the exercise. Not 48
hours later, it was like Ground Hog’s Day: a large earthquake striking off the
Northeast corner of New Zealand. Unlike the exercise, this earthquake
barely met our criteria for activating the Tsunami Experts Panel, but was
scarily close to how the Tangaroa scenario started for us! More on that later.

We’ve had a pretty busy series of aftershocks since then,
and our scientists worked tirelessly to get the Operational Earthquake Forecast
out as quickly as we could. Then…Volcanoes! Ruapehu, and White Island. That’s right, never to be left out of
the action, Mt. Ruapehu decided that it had had enough of a cold crater lake
and that it was time heat things up. And there was a small eruption at White Island. To top it all off, we had a M6.2
off Macquarie Island, 1,000 km south of the South Island (and technically part
of Australia), which caused a M5.3 ghost quake in our automatic system (proving
again we have more work to do!).

GNS Science staff at the science response meeting in the GeoNet Media Room following the M7.1 East Cape earthquake

After all this, it would be easy to just take the weekend
off, put up our feet and drink some kind of adult beverage (single malt and/or
red wine for me thanks). But, we’re GeoNet. We don’t get to rest or stop. We
can’t turn off our phones that wake us up at night. Our project manager is New
Zealand itself; we are on her time. And,
we find that after a busy time, it’s good to sit back and reflect on what we’ve
learned.

Here’s a brief rundown:

Shaking is still the best alert: We love
technology at GeoNet - I personally love technology as I have stated many times.
LOVE. IT. But sometimes technology is not the answer. This is why I want to
thank everyone living on the coast who did it right - felt the earthquake and
evacuated. It’s not an easy decision to make but had the tsunami been
larger…well, let’s not go there. Anyway, well done.

Decision-making with only a little bit of
information is tough: remember I mentioned the Tsunami Expert’s Panel? The
Tsunami Experts Panel is a group of senior scientists from across New Zealand
who advise whether a tsunami will be generated or not and on the potential
impacts. In this case, the source of the earthquake was very strange and with our
instruments confined to the coast, our data was pretty limited. And making decisions with little information
does not come naturally to most trained scientists; we like enough information
to make calm, informed decisions. This is why we partner so well with our
friends at the Ministry of Civil Defence and Emergency Management.

Which is
why…

Partnerships are critical – people were critical
of our friends over at the Ministry of Civil Defence and Emergency Management
and others for the slow or lack of alerting.And we understand, with all the technology, it seems natural that we
should be quicker alerting people. But behind the scenes, it isn’t as straightforward
as pushing a button (that mythical big red button).Ironically, a large event is simpler because
it is well over the threshold for action. For the M7.1 it was well below the
threshold with high uncertainty - higher than any I’ve seen for a while.

And returning to the Exercise Tanagora – that
giant pretend tsunami generated by a pretend M9.1 earthquake 1000 km north of
Tauranga. In the exercise universe the Experts Panel had problems with forecast
model calibration because none of the deep sea buoys (DARTs) in the area were
operational. The news is that this is the real world case – all three DART
buoys north of New Zealand have currently failed. These buoys, which are
operated and maintained by the United States, are the most expensive to repair
because of sea conditions and distance from normal repair facilities. We
understand it will be some time before they are repaired.

People still love the long Felt Reports – we had
so many complaints about our classic Felt Report system that we thought going
to a Rapid system would be universally embraced.Well, we were wrong. So we’ve been putting
together Felt Detailed. We’ve trailed this long form Felt Report, it
still needs some tweaks to be ready for all earthquakes, but we are working on
it. Personally, I’m amazed at how many people are willing to give us feedback
on a survey that takes longer than 20 minutes. But, there you go (personally I
have great problems fill in forms!).

Probabilities are still hard to communicate –
we’ve got all kinds of social science research on how to communicate
probabilities. But even with our table, the scenarios and charts, it is still
hard to discuss probabilities without causing some kind of confusion.So, why bother? Because we think that it is
better to tell people what we know (the probabilities) than not. We’ll keep
trying to get better at it but we know it’s hard.

At GNS Science, we’ve got over 30 staff (and many more from
across the organisation) dedicated to
keeping GeoNet running.I just want to give a massive thank you to my
hard working teams of duty officers, app and website developers, public
information specialists, seismologists, and the technicians who spend hours in
the cold fixing and updating our 600+ instruments throughout the country. You
are individually and collectively awesome!

About Me

I have been the Director of New Zealand GeoNet at GNS Science since 2005. GeoNet is New Zealand’s integrated geological hazards monitor system employing state of the art equipment and telecommunications technology. I am the immediate past chair of the governance group for the Pacific Tsunami Warning and Mitigation System (ICG/PTWS), and a current working group chair.. I am a scientific project manager, seismologist, scientific instrumentation and telecommunications specialist with more than 30 years’ experience. My research has concentrated on geophysical instrumentation, the field studies of large earthquakes, and the study of the deep structure beneath New Zealand and internationally using the seismic waves generated by earthquakes.